JPWO2018150821A1 - Valve device - Google Patents

Abstract

An object of the present invention is to provide a valve device that suppresses deposit adhesion to a gas passage and is excellent in assemblability. The valve device includes a valve body (5), a tubular passage component (30) that is mounted on the valve body (5) and is covered with a fluorine-based resin, and a gas that flows through the gas passage. A throttle valve (2) for controlling the flow rate, a throttle shaft (3) that passes through the passage component (30) and supports the throttle valve (2) in the gas passage, and a bearing that supports the throttle shaft (3) ( 8 and 9), and the passage member (30) has a boss portion (30A, 30B) as a fitting portion that fits with the bearing (8, 9).

Description

  The present invention relates to a valve device.

  As a motor-driven throttle valve control device for an internal combustion engine, one described in Patent Document 1 is known. In the throttle valve control device having such a structure, conventionally, suspended particulate matter in the atmosphere, blow-by gas, exhaust gas recirculated from the exhaust pipe to the intake passage by the EGR device, intake air from the combustion chamber through the intake valve, and the like. There was a problem that deposits were accumulated on the wall surface of the air passage due to the influence of blowing back and the like returned to the passage. If deposit adheres to the wall surface of the intake passage, the air flow rate at a predetermined opening degree decreases, and engine performance decreases such as idling becoming unstable.

  As a measure for preventing such deposit adhesion, as described in Patent Document 2, it has been proposed to provide a surface for preventing fouling on the surface of the air passage.

JP 2012-247323 A JP 2006-322433 A

  However, in the conventional coating method, there is a problem that the performance as a throttle valve device is deteriorated because the deformation and dimensional change of the throttle body constituting the air passage occur due to the heat effect in the coating baking process. there were. In addition, the oil for cleaning the surface of the throttle body is washed away by the cleaning to perform the coating process, and the press-fitting load increases when the parts are assembled by press-fitting work, making normal assembly work difficult. There was also a problem that mass production was difficult.

  According to an aspect of the present invention, a valve device includes a valve body, a tubular passage component that is mounted on the valve body and is covered with a fluorine resin, and that flows through the gas passage. A valve body that controls the flow rate of gas, a valve drive shaft that passes through the passage configuration member and supports the valve body in the gas passage, and a bearing that supports the valve drive shaft. The member has a fitting portion that fits into the bearing.

  ADVANTAGE OF THE INVENTION According to this invention, the adhesion of the deposit to a gas channel | path can be suppressed and the valve apparatus excellent in assemblability can be provided.

FIG. 1 is an external perspective view of a throttle valve device. FIG. 2 is an exploded perspective view of the throttle valve device. FIG. 3 is a diagram showing an axial cross section of the throttle valve device. FIG. 4 is a cross-sectional view of the throttle valve device taken along a plane perpendicular to the axial direction. FIG. 5 is a side view of the throttle valve device with the gear cover removed. FIG. 6 is a diagram illustrating the position of the throttle valve at the default opening. FIG. 7 is a diagram illustrating a modified example of the passage component member.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. Hereinafter, a motor-driven throttle valve will be described as an example of the valve device. However, the present invention is not limited to the following embodiments, and various modifications and applications may be made within the technical concept of the present invention. Examples are also included in the scope. For example, it is attached to the intake passage of an internal combustion engine, and the cross-sectional area of the intake passage is variably controlled to adjust the amount of air taken into the cylinder in a gasoline engine vehicle, or the pressure in the intake pipe in a diesel engine It is used for a valve device for controlling. The gasoline engine vehicle is used for both a so-called in-cylinder direct fuel injection type engine in which fuel is directly injected into a cylinder and a so-called port injection type engine in which fuel is injected into an intake pipe.

  FIG. 1 is an external perspective view of a motor-driven throttle valve device 1 used for a gasoline engine vehicle. The valve body 5 made of aluminum die cast is formed with a bore portion 1A which is a gas passage and a motor housing 20A in which a valve driving motor is housed. A gear cover 26 is fixed to the side surfaces of the valve body 5 and the motor housing 20 </ b> A using a plurality of clips 27.

  2 to 5 are diagrams illustrating the internal structure of the throttle valve device 1. FIG. 2 is an exploded perspective view of the throttle valve device 1 shown in FIG. 3 is a cross-sectional view of the throttle valve device 1 taken along the axial direction of the bore portion 1A, and FIG. 4 is a cross-sectional view taken along a plane perpendicular to the axial direction of the bore portion 1A. FIG. 5 shows the configuration of the reduction gear mechanism and the like with the gear cover 26 removed.

  The valve body 5 is formed with a bore portion 1A. In FIG. 3, the opening on the upper side of the figure becomes the intake port. On the lower side of the bore portion 1A of the valve body 5, a passage constituting member 30 in which a bore portion 1B that is a gas passage is formed is disposed. The passage member 30 is formed of a fluorine resin member having water repellency and oil repellency. As the fluororesin member used for the passage constituting member 30, glass-reinforced PTFE or PFA is preferable.

  As described above, since the passage constituting member 30 formed of the fluorine-based resin member is disposed, the adhesion of deposits to the bore portion 1B can be suppressed by the water repellency and oil repellency of the fluorine-based resin member, and the stain resistance is excellent. A valve device can be obtained. That is, it is possible to prevent a decrease in flow rate due to deposit adhesion.

  The throttle valve 2 made of a metal disk is inserted into a slit provided in the throttle shaft 3 and fixed to the throttle shaft 3 with a screw 4. The throttle shaft 3 is rotatably supported by bearings 8 and 9 provided on the valve body 5. By rotating the throttle shaft 3, the opening degree of the throttle valve 2 disposed in the passage of the bore portion 1B changes, and as a result, the cross-sectional area of the gas passage changes and the intake gas flow rate to the engine is controlled. Is done.

  The bearing 8 is press-fitted into a bearing boss portion 6 formed in the valve body 5. The illustrated right end portion of the bearing 8 protrudes from the inner peripheral surface of the valve body 5 and is fitted to a boss portion 30 </ b> A formed on the outer peripheral surface of the passage constituting member 30. Similarly, the bearing 9 is press-fitted into a bearing boss portion 7 formed in the valve body 5. The illustrated left end portion of the bearing 9 protrudes from the inner peripheral surface of the valve body 5 and is fitted to a boss portion 30 </ b> B formed on the outer peripheral surface of the passage constituting member 30. As a result, the passage constituting member 30 is fixed to the valve body 5 by the bearing 8 and the bearing 9. The fitting between the boss portions 30A and 30B and the bearing 8 and the bearing 9 is a press fit or a clearance fit with a small clearance.

  In this way, the position of the fluororesin-made passage constituting member 30 is regulated by the bearings 8 and 9 that support the throttle shaft 3, so that the shaft hole portion 301 and the shaft hole portion 302 through which the throttle shaft 3 penetrates are connected to the throttle hole 3. Positioning with respect to the shaft 3 can be performed with high accuracy.

  By the way, if the positional accuracy between the shaft hole 301 and the shaft hole 302 and the throttle shaft 3 is poor, the shaft holes 301 and 302 and the throttle shaft 3 are likely to interfere with each other, and the friction increases. In order to avoid such a situation, it is necessary to increase the hole diameters of the shaft hole portions 301 and 302, the flow rate of gas passing through the shaft hole portions 301 and 302 is increased, and the minimum control gas of the throttle valve is increased. There arises a problem that the flow rate becomes large. However, by adopting the positioning configuration using the bearings 8 and 9 as described above, the passage constituting member 30 can be fixed to the valve body 5 without increasing the minimum control gas flow rate.

  Since the axial position of the passage component 30 is positioned by the bearings 8 and 9, there is a slight gap between the fitting surface (upstream end surface) 303 of the passage component 30 and the fitting surface 5S of the valve body 5. Will cause a gap.

  By the way, in the case of an electronically controlled throttle valve, it is designed to return to a predetermined opening (default opening described later) in the event of an abnormality. FIG. 6 is a diagram showing the position of the throttle valve 2 at the default opening. This opening is also called a fail-safe position, and flow rate accuracy at an opening below the fail-safe position is particularly important. Therefore, in the present embodiment, the position of the upstream end surface 303 of the passage component member 30 is arranged upstream of the upstream end 2a of the throttle valve 2 with respect to the position of the throttle valve 2 in the fail-safe position. The position of the downstream end surface 304 is arranged on the downstream side of the downstream end 2b of the throttle valve 2.

  As a result, at least at the opening degree up to the fail-safe position, the gas passage surface opposed to the throttle valve 2 is made of fluororesin, so that deposit accumulation on the gas passage surface is suppressed and the accuracy of flow control is deteriorated. Can be suppressed.

  As shown in FIG. 4, the throttle shaft 3 is disposed along one diameter line of the bore portion 1 </ b> B, one end is supported by the bearing 8, and the other end is supported by the bearing 9. Although a ball bearing is used as the bearing 8 and a needle bearing is used as the bearing 9, both the bearings 8 and 9 may be needle bearings. The bearing 9 is press-fitted into the valve body 5 after being press-fitted into the throttle shaft 3, and then pressed by a cap 10 that is press-fitted into the valve body 5. Thereby, the movable amount of the throttle shaft 3 in the axial direction is restricted.

  The motor 20 composed of a brush type DC motor is disposed in the motor housing 20A so that the motor shaft is substantially parallel to the throttle shaft 3. A wave washer 25 is disposed between the bottom of the motor 20 and the motor housing 20A. As shown in FIG. 2, the flange 20F (see FIG. 5 to be described later) of the bracket 20B of the motor 20 is screwed to the valve body. 5 is fixed to the motor housing 20A.

  The opening of the bearing boss portion 6 is sealed by the bearing 8, and the opening of the bearing boss portion 7 is sealed by the cap 10. The bearing 8 and the cap 10 constitute a shaft seal portion and are configured to be kept airtight. The cap 10 also has a function of preventing the end of the throttle shaft 3 and the bearing 9 from being exposed. With such a configuration, leakage of air from the bearings 8 and 9 or grease for lubricating the bearings is prevented from leaking into the outside air or into a sensor chamber which will be described later.

  As shown in FIGS. 4 and 5, a metal gear 22 having the smallest number of teeth is fixed to the end of the rotating shaft of the motor 20. A reduction gear mechanism and a spring mechanism for rotationally driving the throttle shaft 3 are collectively arranged on the side surface of the throttle body on the side where the gear 22 is provided. These mechanism portions are covered with a gear cover 26 made of a resin material fixed to the side surface portion of the valve body 5.

  The throttle gear 11 is fixed to the end of the throttle shaft 3 on the gear cover 26 side. The throttle gear 11 includes a metal plate 12 and a resin gear portion 13 formed by resin molding on the metal plate 12. A hole for fitting with the throttle shaft 3 is provided at the center of the metal plate 12, and a flange for gear molding is provided on the outer periphery of the metal plate 12. A resin material gear portion 13 is molded on the flange portion by resin molding.

  A screw groove is formed around the tip of the throttle shaft 3. The metal plate 12 is fixed to the throttle shaft 3 by inserting the tip of the throttle shaft 3 into the hole at the center of the metal plate 12 and screwing the nut 17 into the threaded portion. As a result, the throttle gear 11 rotates integrally with the throttle shaft 3.

  Between the back surface of the throttle gear 11 and the default lever 16, a default spring 15 formed by a string spring is sandwiched. Further, a return spring 14 formed of a string spring is sandwiched between the back surface of the default lever 16 and the side surface of the valve body 5. These constitute the default mechanism of the throttle valve 2, and when the return of the motor 20 is turned off by the return spring 14 and the default spring 15 attracting in the opening direction and the closing direction, the throttle valve 2 The opening is defined as a predetermined opening (hereinafter referred to as a default opening).

  Since the present embodiment is a throttle valve device for gasoline, the opening position given as the initial position of the throttle valve 2 when the motor 20 is powered off is the default opening. When the throttle valve 2 is opened more than the default opening, the return spring 14 applies a load in the closing direction toward the default opening. On the contrary, when the throttle valve 2 is closed more than the default opening, the load in the opening direction toward the default opening acts by the default spring 15.

  An intermediate gear 23 is meshed between the gear 22 attached to the rotating shaft of the motor 20 and the throttle gear 11 fixed to the throttle shaft 3. The intermediate gear 23 is rotatably supported by a metal gear shaft 24 that is press-fitted and fixed to the side surface of the valve body 5. The intermediate gear 23 includes a large-diameter gear 23 </ b> A that meshes with the gear 22 and a small-diameter gear 23 </ b> B that meshes with the throttle gear 11. The gears 23A and 23B are integrally formed by resin molding. These gears 22, 23A, 23B, and 11 constitute a two-stage reduction gear mechanism. The rotation of the motor 20 is transmitted to the throttle shaft 3 through such a reduction gear mechanism.

  As shown in FIG. 4, the speed reduction mechanism and the spring mechanism are covered with a gear cover 26 made of a resin material. A groove into which the seal member 31 is inserted is formed at the opening end side periphery of the gear cover 26. When the seal member 31 is mounted in this groove and the gear cover 26 is put on the valve body 5, the seal member 31 comes into close contact with the end face of the frame around the gear storage chamber formed on the side surface of the valve body 5 to store the gear. Shield the room from outside air. As shown in FIG. 1, the gear cover 26 is fixed to the valve body 5 by six clips 27.

  The rotation angle detection device, that is, the throttle sensor formed between the reduction gear mechanism configured as described above and the gear cover 26 covering the reduction gear mechanism will be specifically described below. As shown in FIG. 3, a resin holder 19 is fixed to the end of the throttle shaft 3 on the gear cover side. An inserter 29 is formed integrally with the resin holder 19, and the resin holder 19 is fixed to the throttle shaft 3 by press-fitting the inserter 29 into the end of the throttle shaft 3. As shown in FIG. 5, a conductor 18 formed by pressing is attached to the flat portion at the tip of the resin holder 19 by integral molding. Therefore, when the motor 20 rotates and the throttle valve 2 rotates, the conductor 18 also rotates integrally.

  As shown in FIGS. 3 and 4, a TPS substrate 28 is fixed to the gear cover 26 at a position facing the conductor 18. The ASIC disposed on the TPS substrate 28 detects the angle of the conductor 18, thereby detecting the opening of the throttle valve 2 and supplying it to the ECU as a sensor output. As shown in FIG. 5, the valve body 5 is provided with gear cover positioning walls 5P1, 5P2, and 5P3. The positioning protrusions of the gear cover 26 are locked to the walls 5P1, 5P2, and 5P3, whereby the TPS substrate 28 and the rotating conductor 18 are positioned. As a result, a sensor signal can be output with an accuracy within an allowable range.

  The fully open stopper 11 </ b> A mechanically determines the fully open position of the throttle gear 11, and is constituted by a protrusion integrally formed on the side wall of the valve body 5. When the notch end portion of the throttle gear 11 is in contact with the fully open stopper 11A, the throttle shaft 3 cannot rotate beyond the fully open position. The fully closed stopper 11 </ b> B is a stopper that regulates the fully closed position of the throttle shaft 3. The end on the opposite side of the throttle gear 11 contacts the fully closed stopper 11B in the fully closed position, thereby preventing the throttle shaft 3 from rotating beyond the fully closed position.

(Modification)
FIG. 7 is a view for explaining a modification of the passage constituting member 30. The passage member 30 in the modified example includes a cylindrical metal portion 311 and a fluorine-based resin portion 312 formed on the inner peripheral surface of the metal portion 311. The fluorine-based resin portion 312 is made of the same fluorine-based resin as the passage constituting member 30 shown in FIG. 3, and the inner peripheral surface of the fluorine-based resin portion 312 constitutes a boss portion 1B that is a gas passage. In the configuration shown in FIG. 7, a boss portion 30 </ b> A that is a fitting portion with the bearing 8 and a boss portion 30 </ b> B that is a fitting portion with the bearing 9 are formed in the metal portion 311.

  As described above, in the modification, the passage constituting member 30 is configured by the metal portion 311 and the fluorine-based resin portion 312 so that the entire passage constituting member 30 is formed by the fluorine-based resin member as in the case of FIG. Compared to the case, the mechanical strength can be increased. Moreover, since the fitting part (boss | hub parts 30A and 30B) with the bearings 8 and 9 is formed in the metal part 311, even when press fit is used for fitting, sufficient intensity | strength is ensured to a fitting part. be able to.

According to the embodiment described above, the following operational effects can be obtained.
(C1) Since the cylindrical passage constituting member 30 attached to the valve body has a bore portion 1B which is a gas passage covered with a fluorine-based resin, oil components and condensed water adhere to the bore portion 1B. Can be suppressed. As a result, deposit accumulation on the bore portion 1B is suppressed, and a valve device having excellent antifouling properties can be provided.

  Further, the passage constituting member 30 has boss portions 30A and 30B which are fitting portions fitted to the bearings 8 and 9 that support the throttle shaft 3, and the fitting portions are fitted to the bearings 8 and 9. Thus, the passage component 30 is positioned. Therefore, unlike the conventional case where the gas passage surface of the valve body 5 is coated, there is no deformation or dimensional change of the valve body 5 due to the thermal effect during coating. In addition, the problem of deterioration in assembly work due to cleaning can be avoided.

  Further, since the passage constituting member 30 is positioned by the bearings 8 and 9 that support the throttle shaft 3, the dimension of the gap with the throttle shaft 3 penetrating the passage constituting member 30 can be accurately defined. As a result, the disturbance of the gas flow due to the gap can be suppressed, and the control of the flow rate control can be enhanced.

(C2) Moreover, as shown in the modification of FIG. 7, the passage component member 30 includes a cylindrical metal portion 311 formed with boss portions 30 </ b> A and 30 </ b> B that are fitting portions, and at least an inner periphery of the metal portion 311. It is good also as a structure provided with the fluorine resin part 312 which is formed in the surface and is a fluorine resin layer. By configuring the passage component member 30 with the metal portion 311 and the fluorine resin portion 312, the strength of the passage component member 30 can be improved. Furthermore, since the fitting part is provided in the metal part 311, the strength of the fitting part can be improved.

  (C3) Further, a part of the bearings 8 and 9 may be fixed to the valve body 5. As a result, the passage constituting member 30 is fixed to the valve body 5 via the bearings 8 and 9, and is excellent in assemblability.

(C4) Further, the throttle shaft 3 is driven by the motor 20, and the upstream end position (303) of the passage constituting member 30 is upstream of the upstream end 2a of the throttle valve 2 at the default opening when the motor is off. It is preferable that the downstream end position (304) of the passage component member 30 be disposed downstream of the downstream end 2b of the throttle valve 2 at the default opening. As a result, at least at the opening up to the fail-safe position, the gas passage surface opposed to the throttle valve 2 is made of fluororesin, so that deposit accumulation on the gas passage surface is suppressed, It is possible to suppress deterioration in accuracy of flow control.

(C5) Further, as shown in FIG. 3, the downstream end face of the valve body 5 to which the passage constituting member 30 is mounted constitutes a seal surface S, and is connected to the downstream apparatus via the seal member. Therefore, by disposing the passage component member 30 up to the position of the seal surface S, the end surface of the passage member 30 and the end surface of the valve body 5 can constitute the seal surface S, and the throttle valve device 1 is increased in size. Can be suppressed.

  Although various embodiments and modifications have been described above, the present invention is not limited to these contents. Other embodiments conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention. For example, in the above embodiment, a motor-driven throttle valve control device (motor-driven throttle valve control device) for a gasoline engine vehicle is described as having a cooling water passage portion. It can also be applied to a throttle valve control device of the type. The present invention can also be applied to a mechanical engine throttle valve control device. Furthermore, the present invention can be applied to a throttle valve control device for EGR gas control and a throttle valve control device for generating negative pressure.

  DESCRIPTION OF SYMBOLS 1 ... Throttle valve apparatus, 1A, 1B ... Bore part, 2 ... Throttle valve, 2a ... Upstream end part, 2b ... Downstream end part, 3 ... Throttle shaft, 5 ... Valve body, 6,7 ... Bearing boss part, 8, 9 ... bearing, 20 ... motor, 30 ... passage component, 30A, 30B ... boss, 301, 302 ... shaft hole, 303 ... upstream end face, 304 ... downstream end face, 311 ... metal part, 312 ... Fluorine resin part, S ... Seal surface

Claims (5)

A valve body;
A tubular passage component that is attached to the valve body and has a gas passage covered with a fluorine resin,
A valve body for controlling the flow rate of the gas flowing through the gas passage;
A valve drive shaft that passes through the passage component and supports the valve body in the gas passage;
A bearing for supporting the valve drive shaft,
The said channel | path component member is a valve apparatus which has a fitting part which fits with the said bearing. The valve device according to claim 1,
The said path | route component member is a valve apparatus provided with the cylindrical metal part in which the said fitting part was formed, and the fluororesin layer formed in the at least internal peripheral surface of the said metal part. The valve device according to claim 1 or 2,
A valve device in which a part of the bearing is fixed to the valve body. The valve device according to claim 1 or 2,
The valve drive shaft is driven by a motor,
The upstream end position of the passage component member is disposed upstream of the upstream end of the valve body at the default opening when the motor is off,
The downstream end position of the passage component member is a valve device that is disposed downstream of the downstream end of the valve body at the default opening. The valve device according to claim 4,
The downstream end surface of the valve body on which the passage component member is mounted constitutes a seal surface,
The valve device, wherein the passage component is disposed up to the position of the seal surface.

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